Single use container having a sealed passage adapted to be unsealed upon applicationof stress



Sept. 29, 1953 E. H. LAND 2,653,732

SINGLE USE CONTAINER HAVING A SEALED PASSAGE ADAPTED TO BE UNSEALED UPONAPPLICATION OF STRESS Filed Feb. 5, 1949 1! ti 20 v k hlz Patented Sept.29, 1953 SINGLE USE CONTAINER HAVING A SEALED PASSAGE ADAPTED TO BEUNSEALED UPON APPLICATION OF STRESS Edwin H. Land, Cambridge, Mass.,assignor to Polaroid Corporation, Cambridge, Mass, a corporation ofDelaware Application February 5, 1949, Serial No. 74,791

10 Claims. (01. 222-107) This invention relates to containers and hasfor a principal object the provision of a single use, disposablecontainer so constructed. that its contents can be directly spreadtherefrom in a thin layer to fully cover an area substantially as wideas the container is long and many times the width of the container.

Another object is the provision of a container having an elongatedliquid-containing cavity and a sealed passage adjacent the long edgethereof, so constructed as to be uniformly unsealed throughout a lengthapproximately equal to said cavity upon application of a suitable stressto the walls of the container.

A further object is to provide a novel container of the foregoing typewhich is flat and which, in its filled and sealed condition, is readilyconformable to a curved shape without rupture of its seal, makingpossible the mounting of a plurality of such containers on a strip ofsheet material which can be wound into a roll having a relatively smallradius.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the product possessing the features,properties and the relation of components which are exemplified in thefollowing detailed disclosure, and the scope of the application of whichwill be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawing wherein;

Figure l is a plan view, with parts broken away, of a blank from whichone embodiment of the novel container of the present invention may beformed;

Fig, 2 is a fragmentary, sectional view taken substantially along theline 2-2 of Fig. 1;

Fig. 3 is a perspective view of a portion of the container structure ofthe present invention in its filled and sealed condition;

Fig. 4 is a section, taken substantially along line ?.4 of Fig. 3,showing the details of the sealed liquid-releasing passage of thecontainer;

Fig. 5 is a sectional view showing the container mounted on a suitablebase of a curvature which the container may readily assume withoutrupture; and

Fig. 6 is a somewhat diagrammatic perspective view, with parts brokenaway, illustrating an application of the container of the presentinvention.

Frequently it is required that a small quantity of liquid material beapplied in a relatively thin layer over a fairly large surface area. Forexample, a photosensitive film may be processed or a picture toned byapplying on the surface thereof a layer of liquid containing theprocessing reagent or toning agent in solution. A dye or ink must besimilarly applied to a hand press or printing block for producing sampleprints or impressions. Adhesion of two elements also often necessitatesa continuous layer of the adhesive between surfaces of said elements.The present invention comprehends an inexpensive, disposable containerwhich makes available for such uses only so much liquid as is necessaryfor a single application in a condition for direct application to thesurface to be treated, resulting in greater eiliciency and economy ofoperation.

structurally, the container is elongated, having a length at least twiceits width and is relatively flat, having a depth which is only afraction of its width. The container is deformble in its filled and.sealed condition so that it may be curved in the direction of its width,for example about a radius equal to its width, without danger ofrupturing its seal. A sealed passage extends the length of the containeralong one edge thereof, and is the weakest of the edge seals whichdefine the liquid-containing cavity and which confine the contents insaid cavity.

The contents of the container are of a viscosity exceeding apredetermined minimum viscosity and, in this viscous condition,cooperate with the container structure and the sealed passage to in surea uniform peeling apart of the walls of said sealed passage uponapplication of a squeezing force to the walls of the container. Thisforce is applied to the entire length of the container as by a doctorblade, roll applicator or a pair of pressure rolls, and progresseswidthwise of said container in the direction of the sealed passage. Byequipping the container with a fairly wide, flat, liquid-containingcavity, and by suitably thickening the contents to give the same atleast a predetermined minimum viscosity, the squeezing together of thecontainer walls, particularly during the initial stages of the pressureapplication, insures an equalization of the hydraulic peeling pressuretransmitted by the container contents to the sealed passage prior torupture of the seal. The further squeezing together of the containerwalls during the progressive application of the liquid-releasing forceproduces a uniform and complete peeling apart of the marginal wallswhich constitute the sealed passage.

The container is fluid-tight and substantially water-vapor-impervious sothat its contents may be kept intact for long periods of time, and thestructure thereof is such that the contents of the container can besqueezed and distributed therefrom with the same ease and uniformity atany time during the several months which follow the forming, filling andsealing of the container. As a result the container can be stored forrelatively long periods of time prior to use.

The container is preferably formed from a single, essentiallyrectangular blank folded medially. It may also be formed from twoessentially rectangular blanks secured together at their marginal edges.the blank or blanks from which the same is formed may be out withoutwaste from'a single continuous strip of sheet material, permitting thematerial of the container walls to beprocessed, and the container to befilled, sealed and severed as part of one continuous operation.

Referring to Fig. 1 there is shown a blank I 0 from which one embodimentof the novel container of the present invention may be formed,

said blank, as shown, being substantially rectangular in shape andhaving a length equal to the container length, and a width approximatelytwice the width of the finished, filled container. The blank ispreferably formed of a composite, deformable sheet material comprising aplurality of layers or plies (Fig. 2).

An outer layer 12 serves as a backing or support and is preferablyformed of a thin, relatively inexpensive. tough material which may be aplastic but is preferably a paper, such as kraft paper. Applied to thesurface of layer I2 is a thin film or sheet of a relativelyvapor-impervious material, such as a metal foil [4, and there is coatedon the surface of said foil I4 a further layer l6 of a suitable plasticwhich canbe adhered to itself by the application of heat and/orpressure. Layer [6 is preferably liquid-impervious in order to provide aprotective coating for the metal foil l4, thereby preventing thecontents of the container from reaching the foil to corrode or otherwisedeteriorate the same. Coatings l4 and I6 are relatively thin, being onlysufficiently thick to be continuous.

Adjacent one long edge of the blank I!) there is provided a strip [8 ofa suitable thermoplastic.

material which has a lesser aiiinity for the plastic of layer l6 thanthe latter plastic has for itself. Coating i8 is applied in such a waythat it extends to the very edge of the blank along the entire length ofthe blank, precautions being taken to insure this condition even to theextent of having the material of said strip [8 coated over the edge asshown in Fig. 2.

The container 38 (Fig. 3) is formed by folding the blank along asubstantial medial line 20 extending the length of the container, andthen securing together the faces of the marginal portions 22 along theshort edges of the container and the facing marginal surfaces 24 alongthe long edge of the container. ginal portions are secured together bythe application of heat and/or pressure and, in addition, it ispreferable to adhesively secure together It is so simply constructedthat These several mar- -'the latter bond is substantially stronger thanthe seal along the long edge.

This structure assures a unidirectional release of the'contents of thecontainer upon the application of a compressive squeezing force to theWalls thereof. To make certain that a uniform peeling or separation ofthe marginal portions along the long edge of the container is obtainedwhen the container is subjected to a liquid-releasing force, the strip[8 not only extends to thevery edge of the blank but is alsosubstantially wider than the Width of the seal 24 and extends within theliquid-carrying cavity of the container as shown in Fig. 4. A furtherprecaution against the hazard of an uneven seal consists in displacingthe long edge of the blank containing strip I8 just beyond the long edgeof the blank (Fig. 4) which is adhered thereto. As a result, strip 18projects beyond both long edges of the bond 24.

In the formation of the container, the contents may be introduced as thecontainer walls are being sealed together. For example, the long edgesof the container blank may be sealed together before the blank issevered from the stock of material from which it is formed. During thesealing together of the long edges, the desired quantity of liquidcontent for the container is introduced between the folded walls of theblank and thereafter the short edges are sealed together and thefinished container is severed from the remainder of the sheet stock. Thescaling is preferably effected by the application of heat and/orpressure, and a uniform heat and/or pressure may be applied to all ofthe marginal portions being sealed together in view of the differencebetween the adhesive properties of the strip i8 and those of thematerial of inner coating It.

It is to be expressly understood that a greater strength differentialbetween the short edge seals 22 and the rupturable long edge seal 24 maybe obtained by subjecting the short edge seals to a greater heat and/orpressure during sealing than is used in forming said long edge seal.Similarly, it is possible, although less preferred, to use the samethermoplastic bonding materials for each of the seals 22 and 24 and toobtain the differential sealing effect by controlling the heat and/orpressure used in obtaining the seal, the heat and/or pressure applied tothe short edge seals being substantially greater than the heat and/orpressure applied to the long edge seal.

The walls of container 30 in one preferred form comprise a constructionin which base 12 is a kraft paper, layer I4 is a silver or lead foil,and coating I6 is a thermoplastic such as a polyvinyl acetal, forexample polyvinyl butyral, polyvinyl acetal or polyvinyl formal. It isto be understood that the composition of plastic layer [6 may includesuitable plasticizers and other materials which render the coatingformed from the plastic composition more suitable for its purpose. Forexample, a composition comprising 60% to 72% by weight of polyvinylbutyral, 10% to 23% by weight of nitrocellulose, and approximately 5% byweight of dibutyl sebacate is particularly sat sfactory as inner coatingIt. When layer 16 is of the foregoing composition strip [8 may consistof ethyl cellulose or of a mixture of ethyl cellulose and paraffin, themixture comprising at least 50% by Weight of ethyl cellulose.

As hereinbefore pointed out, the container contents have a predeterminedminimum viscosity and are thickened, if necessary, to impart theretothis predetermined viscosity which cooperates with the seal andstructure of the container to give a uniform and complete opening of thelong seal 24 during use of the container and thereby insure a spreaddirectly from the container over an area as wide as the length of theliquidcontaining cavity of the container. This minimum viscosity shouldbe of the order of at least 1000 centipoises at a temperature of 24 C.Such a viscosity provides adequate allowance for such variations inviscosity as may take place when the container is used in an environmentwhere the temperatures are much higher than 24 C. The range oftemperatures for which the operation of the container is intended is therange of ambient temperatures which would be encountered in variouslocations under varied climatic conditions, i. e., temperatures notexceeding 45 C.

The desired viscosity may be obtained in the liquid content of thecontainer by dissolving in the liquid a suitable high molecular weightpolymer which will not decompose or otherwise lose its thickeningproperties due to reaction with the liquid or the reagents therein. Forexample, where the liquid composition in the container has water as itssolvent, suitable plastics for increasing the viscosity of the liquidcomposition are the water-soluble cellulosic plastics such ashydroxyethyl cellulose and sodium carboxymethyl cellulose.

In one preferred form of the container for spreading a liquid reagent toa thickness of approximately .003 inch over an area approximately 3 x 4inches, a container 3 inches long and having a maximum thickness of 1%inch can be used. The overall width of such a container will beapproximately inch and. the width of seals 24, 22 and 26 will be inch,inch and inch respectively. The overall thickness of the sheet materialfrom which the container walls are formed may be .0048 inch, with layer[2 approximately .0025 inch thick, layer M approximately .0014 inchthick, and layer .0009 inch thick.

As a result of the foregoing structure the con tainer in its filled andsealed condition is relatively deformable, and it becomes possible tomount the container on a suitable base 28 (Fig. 5) of a sheet materialsuch as paper and to wind the paper with the container mounted thereoninto a roll having a radius as small as the width of the container. Inthis way, it becomes possible to package a plurality of the containersin relatively compact and conveniently accessible form.

The use of the novel container structure of the invention is illustratedin Fig. 6 wherein the container contents are applied to an area 32 of asheet material 34 for adhering said area to a corresponding area of asecond sheet material 36. The container 30 is located adjacent to area32 with long seal 24 thereof contiguous to said area, and with saidcontainer between sheet materials 34 and 3B. This arrangement ofelements may be positioned on a plate 58, and a hand-operated squeegeeroller 40 may be advanced over the assembly, beginning its travel atlong edge 26 of the container. The downward pressure apl 6 approximatelyplied by roller will determine the thickness of the film that isobtained when the contents of the container are squeezed from thecontainer. During the early stage of the advance of the roller from theleading edge 26 widthwise of the container there is created a hydraulicpressure in the container contents which is uniformly distributed alongthe entire length of seal 24. Continued advancement of roller 40increases this pressure to the point where the seal is ruptured, therupture uniformly peeling apart the walls of seal 24 to provide adischarge passage for the container contents equal to the length of seal24 between seals 22. The contents may thereafter be spread in a desiredthickness over the area 32 by continued movement of said roller 40, theconstruction of the container insuring an immediate spread Wide enoughto cover said area 32.

It is to be understood that the container 30 may be adhesively orotherwise secured to the sheet 34 over which its contents are to bespread, the latter providing a spreading area adjacent the mouth or lip24 of the container, which area is of a width at least as great as saiddispensing lip is long, and is of a length many times the Width of saidcontainer. Sheet 34 may merely serve as a liquidspreading layer foreffecting a uniform distribution of the liquid content of the containerfor processing an area of another element superposed on said sheet.

The container structure is particularly suited for carrying highlyalkaline solutions such as solutions of photographic developing agentswhose pH may be as high as 14.

This application is in part a continuation of my copending application,Serial No. 652,612, filed March 7, 1946 for Fluid Containers, Patent No.2,634,886, April 14, 1953.

Since certain changes may be made in the above product without departingfrom the scope of the invention herein involved, it is intended that allmatter contained in the above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

1. As a new product, a single use, disposable, container having aliquid-containing cavity extending substantially the length thereof andholding a liquid for spreading directly from said container in a thinlayer over an area substantially as wide as said cavity, said containerhaving a sealed liquid-releasing passage along one edge thereof at leastcoextensive in length with said cavity, said passage comprisinglongitudinal marginal portions of the container walls bonded together inflat, face-to-face relation by a continuous film of adhesive materialinterlaid between the bonded marginal portions over the entire area ofthe bond, said film being applied in a width greater than said bond, thewalls of the container having an inner coating of a thermoplastic resin,said thermoplastic resin having a different aiiinity for itself than forsaid film of adhesive material, said film of adhesive material beingapplied over said coating of thermoplastic resin at the bonded marginal.portions of the container walls so that at said bonded marginal portionsthe film of adhesive material is between the sur faces of thethemioplastic resin.

2. As a new product, a single use, disposable, elongated, substantiallyrectangular, relatively flat container having a liquid-containing cavityextending substantially the length thereof and holding a viscous liquidfor spreading directly from said container in a thin layer over anareasubstantially as wide as said cavity, the viscosity of said liquid beingat least of the order of one thousand centipoises at 24 C., saidcontainer having a sealed liquid-releasing passage along one edgethereof at least coextensive in length with saidcavity, said passagecomprising longitudinal marginal portions of the container walls bondedtogether in flat, face-to-face relation by a continuous film of adhesivematerial interlaid between the bonded marginal portions over the entirearea of the bond, said sealed passage being the weakest liquid-retainingportion of said container, a single sheet of deformable materialimpervious to said liquid and substantially impervious to the vapor ofsaid liquid providing the walls of said container, said sheet having asingle fold extending lengthwise of said container substantiallyparallel to said passage, portions of said sheet adjacent said foldbeing pressed together to provide said container with a fiat, relativelythin, leading edge adapted to offer a minimum resistance to theengagement and advance of a liquidspreading member.

3. As a new product, a single use, disposable,.

substantially rectangular, relatively fiat container having aliquid-containing cavity extending substantially the length thereof andholding a viscous liquid for spreading directly from said container in athin layer, the viscosity of said liquid being at least of the order ofone thousand centipoises at 24 C., said container having a sealedliquid-releasing passage along one long edge thereof, said passagecomprising longitudinal marginal portions of the container walls bondedtogether in fiat, face-to-face relation by a continuous film of adhesivematerial interlaid between the bonded marginal portions over the entirearea of the bond, said sealed passage being the weakest liquid-retainingportion of said container, a single sheet of multi-ply, deformablematerial impervious to said liquid and substantially impervious to thevapor of said liquid providing the walls of said container, said sheethaving a single fold extending lengthwise of said containersubstantially parallel to said passage, the walls of the containerhaving an inner coating of a thermoplastic resin, said thermoplasticresin having a different aflinity for itself than for said film ofadhesive material, said film of adhesive material being applied oversaid coating of thermoplastic resin at the bonded marginal portions ofthe container walls so that at said bonded marginal portions the film ofadhesive material is between the surfaces of the thermoplastic resin.

4. As a new product, a single use, disposable, substantiallyrectangular, relatively flat container having a liquid-containing cavityextending substantially the length thereof and holding a viscous liquidfor spreading directly from said container in a thin layer, theviscosity of said liquid being at least of the order of one thousandcentipoises at 24 0., said container having a sealed liquid-releasingpassage along one long edge thereof, said passage comprisinglongitudinal marginal portions of the container walls bonded together infiat, face-to-face relation by a continuous film of adhesive materialinterlaid between the bonded marginal portions over the entire area ofthe bond, said sealed passage being the weakest liquid-retaining portionof said container, a single sheet of multi-ply, deformable materialimpervious to said liquid and substantially impervious to the vapor ofsaid liquid providing the walls of said container, said sheet having asingle fold exn 1 uu .tendinglengthwise of said container substantiallyparallel to said passage, portions of said sheet adjacent saidfold-being bonded together to provide said container with a fiat,relatively thin, leading edge adapted to offer a minimum resistance tothe engagement and advance of a liquid spreading member, the walls ofthe container having an inner coating of a thermoplastic resin, saidthermoplastic resin having a different aflinity for itself than for saidfilm of adhesive material, said film of adhesive material being appliedover said coating of thermoplastic resin at the bonded marginal portionsof the container walls so that at said bonded marginal portions the filmof adhesive material is between the surfaces of the thermoplastic resin.

5. As a new product, a single use, disposable, substantiallyrectangular, relatively flat container having a liquid-containing cavityextending substantially the length thereof and holding a viscous liquidfor spreading directly from said container in a thin layer over an areaas wide as said cavity, the viscosity of said liquid being at least ofthe order of one thousand centipoises at 24 C., said container having asealed liquid-releasing passage along one edge thereof at leastco-extensive in length with said cavity, said passage comprisinglongitudinal marginal portions of the container walls bonded together infiat, face-toface relation by a continuous film of adhesive materialinterlaid between the bonded marginal portions over the entire area-ofthe bond, said film being applied in a width greater than said bond andextending beyond the bonded area of said marginal portions along bothlong edges of the bond, said sealed passage being the weakestliquid-retaining portion of said container, a single sheet of multi-ply,deformable material impervious to said liquid and substantiallyimpervious .to the vapor of said liquid providing the walls of saidcontainer, said sheet having a single fold extending lengthwise of saidcontainer substantially parallel to said passage, portions of said sheetadjacent said fold being bonded together to provide said container witha fiat, relatively thin, leading edge adapted to offer a minimumresistance to the engagement and advance of a liquidspreading member,the walls of the container having an inner coating of a thermoplasticresin, said thermoplastic resin having a different ailinity for itselfthan for said film of adhesive material, said film of adhesive materialbeing applied over said coating of thermoplastic resin at the bondedmarginal portions of the container walls so that at said bonded marginalportions the film of adhesive material is between the surfaces of thethermoplastic resin.

6. As a new product, a single use, disposable, elongated containerhaving a liquid-containing cavity extending substantially the lengththereof and holding a viscous liquid for spreading directly from saidcontainer in a thin layer over an area as wide as said cavity, theviscosity of said liquid being at least of the order of one thousandcentipoises at 24 C., said container having a sealed liquid-releasingpassage along one edge thereof at least coextensive in length with saidcavity, said passage comprising longitudinal marginal portions of thecontainer walls bonded together in fiat, face-to-face relation by a bondof substantially uniform strength, said sealed passage being the weakestliquid-retaining portion of said container, a single sheet of deformablematerial impervious to said liquid and substantially impervious to thevapor of said liquid providing the walls of said container, said sheethaving a single fold extending lengthwise of said containersubstantially parallel to said passage, portions of said sheet adjacentsaid fold being bonded together to provide said container with a flat,relatively thin, leading edge adapted to offer a minimum resistance tothe engagement and advance of a liquidspreading member.

7. As anew product, a single use, disposable container having aliquid-containing cavity extending substantially the length thereof andholding a liquid for spreading directly from said container in a thinlayer, said container having a sealed liquid-releasing passage along oneedge thereof paralleling said cavity, said passage comprisinglongitudinal marginal portions of the container walls bonded together inflat, face-to-face relation by a continuous film of adhesive materialinterlaid between the bonded marginal portions over the entire area ofthe bond, said film of adhesive material covering a portion only of theinner surface of the container walls, marginal portions of saidcontainer walls along two other edges of said container at opposite endsof said liquidreleasing passage being adhesively secured together inface-to-face relation, the seals at said two other edges beingappreciably stronger than the seal at said passage and extendingtransversely of and connecting with the seal at said passage so thatwhen the walls of the container are squeezed together in the directionof said passage the seal at said passage ruptures and the seals at saidtwo other edges prevent the discharge of liquid except through saidpassage.

8. As a new product, a single use, disposable container having aliquid-containing cavity extending substantially the length thereof andholding a liquid for spreading directly from said container in a thinlayer over an area as wide as said cavity, said container having asealed liquidreleasing passage along one edge thereof at leastcoextensive in length with said cavity, said passage comprisinglongitudinal marginal portions of the container walls bonded together inflat, faceto-face relation by a bond of substantially uniform strength,said sealed passage being the weakest liquid-retaining portion of saidcontainer, marginal portions of said container walls along two otheredges of said container at opposite ends of said liquid-releasingpassage being adhesively secured together in face-to-face relation, theseals at said two other edges being appreciably stronger than the sealat said passage and extending transversely of and connecting with theseal at said passage so that when the walls of the container aresqueezed together in the direction of said passage the seal at saidpassage ruptures and the seals at said two other edges prevent thedischarge of liquid except through said passage.

9. As a new product, a single use, disposable, elongated containerhaving a liquid-containing cavity extending substantially the lengththereof and holding a viscous liquid for spreading directly from saidcontainer in a thin layer over an area as wide as said cavity, theviscosity of said liquid being at least of the order of one thousandcentipoises at 24 C., said container having a sealed liquid-releasingpassage along one edge thereof at least coextensive in length with saidcavity, said passage comprising longitudinal marginal portions of thecontainer walls bonded together in fiat, face-to-face relation by a bondof substantially uniform strength, said sealed passage being the weakestliquid-retaining portion of said container, a single sheet of multi-ply,deformable material impervious to said liquid and substantiallyimpervious to the vapor of said liquid providing the walls of saidcontainer, said sheet having a single fold extending lengthwise of saidcontainer substantially parallel to said passage, said marginal portionsof said container walls along two edges of said container at oppositeends of said liquid-releasing passage and said fold being adhesivelysecured together in face-to-face relation, the seals at said two otheredges being appreciably stronger than the seal at said passage andextending transversely of and connecting with the seal at saidliquid-releasing passage so that when the walls of the container aresqueezed together in the direction of said passage the seal at saidpassage ruptures and the seals at said two other edges prevent thedischarge of liquid except through said'passage.

10. As a new product, a single use, disposable container having aliquid-containing cavity extending substantially the length of onedimension of said container and holding a liquid for spreading directlyfrom said container in a thin layer over an area substantially as wideas the length of said cavity, said container having a sealedliquid-releasing passage along one edge thereof at least coextensive inlength with said cavity, said passage comprising marginal portions ofthe container walls bonded together in flat, faceto-face relation by acontinuous film of adhesive material interlaid between the bondedmarginal portions over the entire area of the bond, the walls of thecontainer having an inner coating of a resin, said resin having adifferent affinity for itself than for said film of adhesive material,said film of adhesive material being applied over said coating of resinat the bonded marginal portions of the container walls so that at saidbonded marginal portions the film of adhesive material is between thesurfaces of the resin.

EDWIN H. LAND.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,885,670 Avery Nov. 1, 1932 2,103,389 Salfisberg Dec. 28,1937 FOREIGN PATENTS Number Country Date 7,521 Great Britain Mar. 28,1906 234,484 Switzerland Jan. 16, 1945

